NASA Readies Microscope for Space Mission

BROOK PARK, Ohio -- Scientists at NASA's Glenn Research Center in Cleveland and Dynacs Engineering are adapting a microscope for the International Space Station's fluid combustion facility. They are motorizing most of the microscope's functional controls and enabling remote control from the ground. Experiments using the light microscopy module could accelerate research in optical bandgap materials.

The light microscopy module is based on an automated DM RXA microscope from Leica Microsystems Inc. of Deerfield, Ill. Along with sensors and video cameras, it will monitor experiments conducted on the lab's fluids integrated rack and relay the images to Earth.

The microscope's autofocus, automatic objective and filter wheel positioning, and remote stage control made it a suitable choice for adaptation, according to John Eustace, a researcher from Dynacs. Capable of bright-field, dark-field, phase contrast and interference contrast techniques, the microscope will be enhanced with instrumentation for light-scattering measurements and spectroscopy, and with laser tweezers for sample manipulation.

Adapting to space

Before its 2003 launch, the microscope also must be prepared for outer space. The researchers must harden the instrument and the lamps against vibration, and must eliminate any materials that could emit hazardous gases. They will coat the electric components to eliminate sparking, convert all power supplies to DC operation and remove all manual interfaces, including knobs and buttons.

Eustace said they will implement additional automated techniques, and add laser interfaces at both the input and output for performing light-scattering measurements. In addition, the team will redesign the trinocular output to fit the space in the fluids integrated rack and to allow switching between imaging and light-scattering modes.

The fluid experiments that the microscope will image are multifaceted. In one, the microscope will image the interference fringes caused by a thin fluid film in a cuvette. In three others, it will image colloidal particles in small cells. Besides imaging particles, the light scattering and laser tweezer subsections of the microscope will be used to interact with the samples. The purpose of all of these experiments is to grow colloidal crystals -- minute particles suspended in a fluid that crystallize under the right conditions.

Eustace predicted that this research may one day lead to the manufacture of optical bandgap materials and to applications such as optical computing. He added that it "is analogous to the research on semiconductors in the first half of this century -- the applications far exceeded anybody's imagination."